The present invention relates to animal test chambers for testing the effect of a chemical agent on animals such as insects. More particularly it relates to test chambers with improved accuracy, consistency, efficiency, and/or versatility.
The efficacy of an insecticide is typically tested in a Peet-Grady chamber, an approximately 6 cubic meter box-like room named after its initial developers. A conventional Peet-Grady chamber has a tight-fitting door for accessing the inside of the chamber, an observation window for observing and counting insects from outside the chamber, various ports on the side walls of the chamber for introducing insects and chemical agents into the chamber, an exhaust opening in the ceiling connected to an exhaust duct for removing insecticide vapor from the chamber, and sometimes a removable grid marked paper on the chamber floor for assisting the counting of the knocked-down insects. Insects are “knocked down” if they are incapacitated and rendered inactive, whether or not actually dead.
To operate such a chamber, one closes the chamber door tightly, closes all ports including the exhaust, introduces a plurality of insects (e.g., mosquitoes or house flies) into the chamber, allows the insects to acclimate to the chamber environment for a minute or two, dispenses the test chemical agent in the chamber, and counts the number of knocked-down insects on the chamber floor. At the end of the test, the total number of insects is counted. This is typically done by a user entering into the chamber and catching the insects that are not knocked-down one-by-one with a vacuum. The user also picks up the knocked-down insects from the floor grid one-by-one with the vacuum.
After each test, the user turns on the exhaust fan to remove insecticide vapor from the chamber. The user then usually washes the chamber walls, floor, and any other devices in the chamber manually with a sponge and water containing mild detergents (e.g., household detergents). The chamber walls and floor are then left to dry after which the chamber is ready for the next test.
The conventional Peet-Grady chamber and its use, as described above, has several drawbacks. Although conventional Peet-Grady chambers have been used with success for testing the effect of a chemical agent dispensed from an aerosol can, various features are significantly inconvenient and require manual operation and associated delays. For example, dosing a chamber with an aerosol requires a complex combination of manual operation of the aerosol can plus use of timed shutters to measure out the dose of spray.
Another drawback of a conventional Peet-Grady chamber relates to the counting grid on the chamber floor. Typically, the floor of a Peet-Grady chamber is covered with a grid sheet. This introduces the extra step of removing and disposing contaminated sheets after each test.
Yet another drawback of a conventional Peet-Grady chamber relates to the inefficiency of preparing the chamber for the next test cycle. The conventional Peet-Grady chamber is manually washed after each test, a process that is time consuming and relatively labor intensive, and may expose the user to several chemicals.
Further, a conventional Peet-Grady chamber is not specifically equipped to bleed air in and out of the chamber during a testing period. Tests are typically conducted in static air with all ports closed. Thus, a test designed to mimic real life housing conditions, where open doors and windows result in air circulation, cannot be readily conducted with a conventional Peet-Grady chamber.
Hence, a need exists for an improved Peet-Grady type chamber.